Hard to believe, but Republicans once took the lead in environmental protection and conservation: Richard Nixon proposed the creation of the Environmental Protection Agency and signed the law establishing it in 1970. George Bush (#41) signed an important extension of the Clean Air Act in 1990 and made the U.S. a signatory to the international treaty that paved the way for the Kyoto Treaty on climate change. Theodore Roosevelt pioneered the creation of the country’s national parks.

Then there is today.

In an eye-opening essay in Environment magazine, two scholars examine the partisan divide on the leading environmental issue of the day, global warming. Sociologists Riley E. Dunlap of Oklahoma State University and Aaron M. McCright of Michigan State University trace this to the Reagan administration’s calling environmental regulations a burden on the economy and to the anti-environmental bent of the Republicans who took control of Congress (led by Newt Gingrich) in 1994. But a partisan divide that was originally most apparent among “political elites, such as members of Congress, who tend to be more ideologically polarized than the general public,” has now spread, the authors write. As recently as the mid-1990s Democratic voters supported increased spending on environmental protection at rates only 10 percent higher than self-identified Republicans, but that gap is now a chasm.

To wit:

• 76% of Democrats believe global warming is already happening; 42 percent of Republicans do, according to a Gallup poll. (In 1997, nearly identical percentages of Republicans and Democrats—48 and 52 percent, respectively—said they thought global warming was already happening.)
• Does the press exaggerate the seriousness of global warming? 17% of Democrats say yes; 59% of Republicans do—a gap of 42 points.
• Do most scientists who study climate change agree that it is empirically established? 75% of Dems say yes, compared to 54% of Republicans.
• Is that warming natural or caused by human activities? 72% of Dems say it’s the latter, but only 40% of Republicans do.
• Will global warming pose a serious threat during our lifetime? 49% of Dems say yes, vs. 26% of Republicans.

Perhaps these gaps are yet another reflection of political polarization, write Dunlap and McCright, including the movement of those who hold one or another belief about climate change to the party that embodies that view, something called “party sorting.”

Interestingly, John McCain has for years taken a position closer to the Democrats, sponsoring legislation (never passed) to control emissions of carbon dioxide. On this issue, write the authors, McCain’s “positions are much closer to Obama’s than they are to almost all of his Republican congressional colleagues. Both McCain and Obama support a mandatory cap on carbon emissions and a high percentage emissions reductions target by 2050 (though Obama’s target is higher). . . . If McCain becomes the next U.S. president, his views on climate change may lead to a shift in the views of some Republicans, but probably not those who have bought into the staunch skepticism of current party elites.” Unless, of course, he defers to his running mate’s interesting views on climate (Sarah Palin does not believe the changes already underway are caused by human activities that add carbon dioxide to the atmosphere) and other scientific issues.